Aaron Ciechanover could not have predicted that the humble system he was studying would play a central role in everything that happens from embryonic development to adulthood. Of course he was just a graduate student at the time. “We didn’t set out to identify ubiquitin. We didn’t know anything about ubiquitin or its function,” says Ciechanover of the discovery that earned him and his mentors the 2004 Nobel Prize in Chemistry. “We were studying intracellular proteolysis and we bumped into it.”
These days, even undergrads know that eukaryotic cells use ubiquitin as a sort of molecular “kiss of death” to mark its damaged proteins for destruction. What’s more, death-by-ubiquitination serves as a key mechanism for controlling tightly regulated cellular processes from cell division to cell death. But in the late 1970s, the notion that cells willfully discard their proteins was not a very popular one. “If you thought protein breakdown ...
